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Changes in mechanical and physical properties of polyurethane thermoplastic during aging at 70 °C and 90 °C were investigated. The loss weight response was analyzed by gravimetric measurements under these temperatures. Changes in appearance and morphology of TPU after thermal aging were revealed by optical microscopy. The prolongation of the thermal exposure time, up to 270 days, leads to a progressive increase in tensile strength. In fact, elastic modulus and stress at 200% of strain were increased with thermal exposure time. These results can be explained by the increase of thermal stability due to the increase of material rigidity and the decrease in chain mobility. The evolution of the mechanical properties from tensile tests seems to be well correlated to the creep behavior. Finally, Scanning Electron Microscopy (SEM) revealed the modification of TPU morphology fracture surface after thermal aging. 相似文献
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Boubakri L. Al-Ayed Abdullah S. Mansour L. Harrath A. A. Al-Tamimi J. Özdemir I. Yasar S. Hamdi N. 《Transition Metal Chemistry》2019,44(4):321-328
Transition Metal Chemistry - The carbonylative Suzuki cross-coupling of 2-bromopyridine with various boronic acids to prepare unsymmetrical arylpyridine ketones has been carried out using... 相似文献
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Chiheb Mhiri Lamia Boubakri Riadh Ternane Lamjed Mansour Abdel Halim Harrath J. Al-Tamimi Lassaad Baklouti Naceur Hamdi 《Journal of heterocyclic chemistry》2020,57(1):291-298
Three-component reaction of arylaldehydes with malononitrile and 4-hydroxycoumarine using CH3COONH4 as a catalyst at reflux was used for the synthesis of novel substituted pyrano[3,2-c]chromene derivatives. The structure of these compounds was assigned by spectroscopic data such as (IR, 1HNMR, 13CNMR, and mass spectral data). The cation binding properties of chromene derivatives 4a-c towards Cu2+, Ni2+, and Zn2+ were studied in methanol. The results showed that Zn2+ is the most complexed in this series of cations, and 4c is best complexed with either Ni2+ and Zn2+. Antimicrobial properties of new pyrano[3,2-c]chromene derivatives are investigated, the compound 4c presents against Micrococcus luteus LB 14110 an MIC value of 0.0185 mg/mL quite better to that of ampicillin (0.0195 mg/mL) used as standard. Concerning acetylcholinesterase inhibition activity (AChEI), compound 4c presents an interesting AChEI activity with an inhibition of 52%. 相似文献
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Lamia Boubakri Khaireddine Dridi Abdullah Sulaiman Al-Ayed İsmail Özdemir Sedat Yasar 《Journal of Coordination Chemistry》2019,72(3):516-527
New palladium complexes were efficiently synthesized from the reaction of benzimidazolium salts 2a–e, potassium carbonate (K2CO3) and palladium chloride (PdCl2) in pyridine (for 3a–e). The catalytic activity of these complexes in a catalytic system including palladium complexes and K2CO3 in DMF-H2O was evaluated in Suzuki–Miyaura cross-coupling reactions of aryl bromides and chlorides with phenylboronic acid. Our novel complexes show excellent catalytic activities with high turnover numbers (TON) and high turnover frequencies (TOF) (e.g. for the Suzuki–Miyaura reaction: TON up to 370 and TOF up to 123.3?h?1). Both benzimidazolium salts 2a–e and complexes 3 have been characterized using spectroscopic data and elemental analysis. The antimicrobial activity of the N-heterocyclic carbene palladium complexes 3a–e varies with the nature of the ligands. Also, the IC50 values of both, complexes (3a–e) and benzimidazoles 2a–e, have been determined. In addition, the new palladium complexes were screened for their antitumor activity. Complexes 3e and 3d exhibited the highest antitumor effect with IC50 values 6.85?μg/mL against MCF-7 and 10.75?μg/mL against T47D, respectively. 相似文献
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L. Boubakri L. Mansour A. H. Harrath I. Özdemir 《Journal of Coordination Chemistry》2018,71(2):183-199
A novel series of N-heterocyclic carbene-phosphine palladium(II) complexes has been synthesized and fully characterized by IR, 1H NMR, 13C NMR, and 31P NMR spectroscopies, and elemental analysis. The new N-heterocyclic carbene (NHC)-phosphine palladium(II) complexes 3a–h have been easily prepared by the reaction of the corresponding PEPPSI (pyridine-enhanced precatalyst preparation stabilization and initiation) complexes 2a–h and triphenylphosphine in dichloromethane in high yields. These complexes were applied as catalyst precursors which efficiently catalyzed Sonogashira reactions between aryl bromides and phenylacetylene to afford the corresponding products in good yields. The bulky NHC-Pd-PPh3 complexes 3 were tested against Gram-positive and Gram-negative bacteria to study their biological activity. All the complexes exhibit antibacterial against these organisms. Investigation of the anti-acetylcholinesterase activity of the studied complexes showed that compounds 3a and 3b exhibited moderate activity at 100 μg mL?1 and product 3b is the most active. 相似文献
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Mohamed Amine Djebbi Saber Boubakri Mohamed Braiek Nicole Jaffrezic‐Renault Philippe Namour Abdesslem Ben Haj Amara 《Electroanalysis》2020,32(6):1186-1197
Nanocomposite of nanoscale zero‐valent iron (nZVI) and layered double hydroxide (LDH) was used as modifier for boron‐doped diamond electrode in determination of anti‐psychotic drug chlorpromazine (CPZ). nZVI nanoparticles were prepared by liquid phase reduction of ferric chloride with sodium borohydride on the surface of NiAl LDH matrix owing to the strong exchange and confinement efficiency of LDH. The structure, binding and surface properties of the nZVI@LDH nanocomposite were monitored using powder X‐ray diffractometry, FT‐IR spectroscopy, scanning and transmission microscopy and BET techniques. The electrochemical properties of the modified electrode were investigated by CV and EIS, performed in a phosphate buffer containing ferro/ferricyanide as redox probe. The modified electrode exhibited excellent electrochemical performance compared with unmodified electrode. As regard potential application of the nanocomposite surface to the CPZ detection, square‐wave voltammetric signals showed a good linear correlation over CPZ concentrations in a broad range from 0.1 to 8.0 μM with low detection limit of 0.005 μM. Nevertheless, these results suggest that the proposed nanocomposite modifier surface provides exceptional synergy and significant enhancement effect to the voltammetric response of CPZ and thus could be applied as highly efficient and stable platform of sensors in clinical analysis. 相似文献
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Boubakri A. Koumya Y. Rajira A. Almaggoussi A. Abounadi A. Achargui N. 《Journal of Solid State Electrochemistry》2023,27(5):1061-1074
Journal of Solid State Electrochemistry - SnS thin films were electrodeposited onto ITO-coated glass substrates using one-step potentiostatic electrodeposition in a bath solution consisting of tin... 相似文献
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Mabrouk Walid Jebri Sonia Charradi Khaled Silimi Bishir Alzahrani Abdullah Y. A. Boubakri Ali Ghodbane Ouassim Raouafi Noureddine Keshk Sherif. M. A. S. 《Journal of Solid State Electrochemistry》2023,27(4):991-999
Journal of Solid State Electrochemistry - In this study, graphene (G) was blended with sulfonated polyether sulfone octyl sulfonamide (SPESOS) in different ratios (1, 1.5, and 2 wt.%) to enhance... 相似文献
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